Application 163

Medical Valve Sensors: TAVR Fatigue Testing

Application Summary

Transcatheter valve replacement is a minimally invasive valve replacement technique that enables valve replacement without the need for open heart surgery. TAVR and TVMR valves are inserted via catheter, inflated and locked into place with a balloon. The bovine pericardial tissue and the bio-compatible metal support structure need to withstand the fatigue of opening and closing in rhythm with a beating heart. To test the fatigue resistance of the valve, a load cell is coupled between a linear actuator and a syringe piston that is pumped up and down to simulate the forces inside a beating heart.

Products in Use

One LSB S-Beam Tension and Compression Load Cell paired with a USB220 High Resolution USB Output Module or IAA Series Analog Amplifier.

How it Works

LSB series load cells are threaded in-line with a linear actuator and syringe piston which measures the force the linear actuator applies to the syringe piston for test validation.
As the linear actuator pushes down on the load cell/piston the flow of fluid pushes the TAVR valve open.
A check valve keeps the fluid moving through the TAVR valve and a reservoir prevents the system from pushing air which would invalidate the test.
The linear actuator then retracts, pulling the piston up, thereby forcing the TAVR closed and refilling through the now open check valve.
This cycling allows for testing of the durability of the replacement valve in a simulated aortic environment for compliance with ISO 5840 series standards.
The USB220 displays and logs the data to a PC via our SENSIT™ software. This data can be used to validate the accuracy and precision of the pressure generated by the syringe piston.
The IAA series amplifier, amplifies the signal for use in DAQs that cannot accept a mV/V signal.